Correct unnecessary builder reassignment

codahale-aggregated-metrics-cloudwatch-reporter's with* methods are
mutating the builder object itself, so there's no need to reassign the
mutated object to itself from the caller.

This allows to make the CloudWatchAsyncClientBuilder final, which in
turns helps the compiler, improves readability and allows to use the
value in lambdas.

Change-Id: I0bdf608f1c9649f4a139eb3fdd6b6fc8062041d8

src/main/java/com/googlesource/gerrit/plugins/metricsreportercloudwatch/GerritCloudwatchReporter.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/metricsreportercloudwatch/GerritCloudwatchReporter.java b/src/main/java/com/googlesource/gerrit/plugins/metricsreportercloudwatch/GerritCloudwatchReporter.java
index 56b6769..8cafca5 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/metricsreportercloudwatch/GerritCloudwatchReporter.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/metricsreportercloudwatch/GerritCloudwatchReporter.java
@@ -33,7 +33,8 @@
       throws IllegalStateException {
     this.config = config;
 
-    CloudWatchAsyncClientBuilder cloudWatchAsyncClientBuilder = CloudWatchAsyncClient.builder();
+    final CloudWatchAsyncClientBuilder cloudWatchAsyncClientBuilder =
+        CloudWatchAsyncClient.builder();
 
     CloudWatchReporter.Builder cloudWatchReporterBuilder =
         CloudWatchReporter.forRegistry(
@@ -46,11 +47,11 @@
             .withHighResolution();
 
     if (config.getDryRun()) {
-      cloudWatchReporterBuilder = cloudWatchReporterBuilder.withDryRun();
+      cloudWatchReporterBuilder.withDryRun();
     }
 
     if (config.getJvmMetrics()) {
-      cloudWatchReporterBuilder = cloudWatchReporterBuilder.withJvmMetrics();
+      cloudWatchReporterBuilder.withJvmMetrics();
     }
 
     cloudWatchReporter = cloudWatchReporterBuilder.build();